In general, a smart blind is a blind capable of adjusting transmittance of light from the sun, and is referred to as a smart window, an electronic curtain, a transmission-variable glass, or a photochromic glass.
For example, the smart blind may be composed of a light transmission rate-adjusting layer capable of adjusting the transmission rate of light, and a driver circuit configured to apply a signal to the light transmission rate-adjusting layer to control the light transmission rate-adjusting layer. The smart blind configured thus may allow light to transmit or not to transmit the entire glass according to a state of applied voltage, and also may vary the shade by controlling the transmission rate. However, the above-described method has a problem in that a power supply system has a complicated structure since an additional external power source should be provided to drive the smart blind.
In recent years, a technique of manufacturing a smart blind by combining a polarizing plate and a retardation film has been developed not to require an additional external power source as disclosed in the patent document 1. A liquid crystal film which is patterned into regions having optical axes in different directions has been generally used as the retardation film. In this case, the retardation film has a problem in that a fine deviation in optical axis on a lateral surface of the smart blind results in ununiformity in optical characteristics, which makes impossible to realize uniform visual sensitivity on the lateral surface of the smart blind.